1. Field of the Invention
The present invention relates to a multilayer ceramic capacitor and, more particularly, a high capacity multilayer ceramic capacitor having excellent reliability and able to withstand insulation breakdown even at a high voltage.
2. Description of the Related Art
In general, an electronic component fabricated using a ceramic material, such as a capacitor, an inductor, a piezoelectric device, a varistor, a thermistor, or the like, generally has a ceramic body made of a ceramic material, internal electrodes provided in the ceramic body, and external electrodes (that is, termination electrodes) placed on surfaces of the ceramic body so as to be connected to respective internal electrodes.
Among ceramic electronic components, a multilayer ceramic capacitor has beneficial features such as small size but high capacity, ease of mounting, and the like, and is therefore widely used as a component of mobile communications equipment such as computers, PDAs, mobile phones, and so forth.
In recent years, with the trend towards smaller sized multi-functional electronic products, electronic parts have tended to have a smaller size and high performance. In response, high capacity multilayer ceramic capacitors having a large capacity while having a small size are required. Accordingly, a multilayer ceramic capacitor, in which thicknesses of dielectric layers and internal electrodes are decreased, such that the dielectric layers and internal electrodes are highly-multilayered, is currently being manufactured.
However, with a decrease in a thickness of dielectric layers and an increase in the number of multilayered dielectric layers, a difference in density between an effective capacity portion having an internal electrode formed thereon and a margin portion having no internal electrode formed thereon is considerably increased. As a result, the margin portion may be delaminated or cracked to thereby allow a plating solution to penetrate thereinto, whereby a deterioration in reliability of the multilayer ceramic capacitor may be caused.
Meanwhile, in a case in which a thickness of a dielectric layer is decreased to thereby allow for an increase in voltage per unit thickness, the dielectric breakdown of the dielectric layer may be possibly caused even when a low voltage is applied thereto.
In particular, when a cross-section of the capacitor is viewed in a width and thickness direction, both ends of an internal electrode in the width direction may have a wedge shape as the internal electrode extends during compressing, such that an electric field strength at the both ends may be more increased due to a notch effect. In addition, a high electric field strength is overlapped at the ends of adjacent internal electrodes in a lamination direction, thus easily causing dielectric breakdowns. Therefore, there are limitations in the development of a high capacity multilayer ceramic capacitor and the miniaturization thereof.